The present disclosure relates to an electronic device, and more particularly, to management of a variety of specific information which identifies the electronic device.
As a kind of an electronic device, a field device has been known which is configured to measure information such as a flow rate, a temperature and a pressure of a measuring target so as to control a plant, for example. FIG. 10 is a configuration view illustrating an example of the related-art field device. In FIG. 10, the field device includes a sensor 1 and a transmitter 2. The sensor 1 and the transmitter 2 are separately configured, so that the sensor 1 and the transmitter 2 are connected to each other through a signal/excitation cable 3.
The sensor 1 is provided at a pipe 4 in which a fluid flows, and a signal relating to a flow rate is output to the transmitter 2 through the signal/excitation cable 3.
The device specific information of the sensor 1 (which is the information identifying the sensor 1) includes the information, which is set upon factory shipment or upon mounting of the device, for example:                an aperture diameter,        a serial number,        a manufacturing date,        client designation information,        a flow rate correction coefficient,        a zero point-adjusted value,        a coil insulation resistance value,        a coil resistance value,        a signal insulation resistance value and the like.        
Here, the zero point-adjusted value is a value obtained by offsetting an unfavorable gentle change or movement of a zero point, which occurs in a relation of an input and an output of the apparatus for a predetermined time period, irrespective of external factors of the device, upon the factory shipment or upon the mounting. A value of the zero point is varied due to problems and the like around an excitation circuit.
The coil insulation resistance value is an insulation resistance value between a coil and a common or between a coil and a signal, which normally has several MΩ. The insulation resistance value is lowered by deterioration of the sensor, for example.
The coil resistance value is a resistance between excitation lines. The coil resistance value is different depending on the aperture diameter or lining, and normally has a resistance value of ±10%. The resistance value is varied depending on coil abnormality temperature changes of fluid/atmosphere, and the like.
The signal insulation resistance value is an insulation resistance value between a coil and a common or between a signal and a signal, which normally has hundreds of M Ω. As described above, the insulation resistance value is lowered by the deterioration of the sensor, for example.
The device specific information is described on a nameplate 11 of the sensor 1, for example. An operator checks the device specific information with eyes and inputs the same to the transmitter 2.
FIG. 11 is a basic configuration view of an electromagnetic flow meter that has been used as a field device. In FIG. 11, the parts common to FIG. 10 are denoted with the same reference numerals. In FIG. 11, a liquid-contacting part of a pipe forming a flow path is made of a material having electrical insulation. An outer periphery of the pipe 4 is provided with yokes 1a facing each other and made of a magnetic material, and coils 1b are wound on the respective yokes 1a. The coils 1b are excited by an excitation unit 1c. 
An inner periphery of the pipe 4 is provided with measuring electrodes 1d and an earth electrode 1e. The measuring electrodes 1d are provided to face each other and configured to detect a signal proportional to a magnetic field formed by the yokes 1a and the coils 1b and a flow rate signal.
Signals output from the measuring electrodes 1d are impedance-converted by buffers 1f and are then input to a differential amplifier 1g. The differential amplifier 1g is configured to remove an exogenous noise occurring commonly to the pair of measuring electrodes 1d, to amplify the signal to a desired amplitude level and to input the same to an A/D converter 1h. 
The A/D converter 1h is configured to perform A/D conversion so that an analog signal generated at the measuring electrode 1d can be read with a digital value.
A CPU 1i is configured to control a whole circuit, to calculate a flow rate value and an integrated value by using the A/D conversion value of the A/D converter 1h and to perform calculation for diagnosing respective units. Also, the CPU is configured to transfer information of the calculation results to an output circuit 1j, to instruct the output circuit 1j to display the flow rate output value and the diagnosis result, and to control the excitation unit 1c by using an A/D conversion value of an A/D converter 1k. 
Here, when the combination of the sensor 1 and the transmitter 2 is fixed, it is preferable to input the device specific information of the sensor 1 to the transmitter 2. Actually, however, the combination of the sensor 1 and the transmitter 2 is not always fixed.
That is, the combination of the sensor 1 and the transmitter 2 may be changed upon the mounting of the field device, upon the repair maintenance, and the like.
When the combination of the sensor 1 and the transmitter 2 is changed, it is necessary to input the changed device specific information of the sensor 1 to the transmitter 2 to which the sensor 1 is actually connected.
Patent Document 1 discloses a technology capable of preventing an incorrect input of a device specific parameter by seeing the same with eyes and effectively updating data of a plurality of electronic devices.
[Patent Document 1] Japanese Patent Application Publication No. 2012-37696A
When inputting the device specific information of the sensor 1 to the transmitter 2, an incorrect input of the device specific information may have a bad influence on a measurement result.
Also, when the sensor 1 is mounted at a place that is out of an operator's reach, it is not possible to easily check the device specific information of the sensor 1, so that the check operation carries a risk.
Also, when it is difficult to check the information described on the nameplate 11 with eyes due to the aging degradation, the high man-hour is caused as to the check operation of the information or the re-calibration is required in some cases.
Also, the necessary information should be re-input whenever the combination of the sensor 1 and the transmitter 2 is changed, so that working man-hour for re-inputting the necessary information is caused.
Further, when the operator performs the input with a hand, it is difficult to easily increase the amount of information to be input, so that the amount of information to be input is limited. Also, a possibility that a human error such as a clerical error and forgetfulness of filling-up will occur increases.